检索结果-南通市图书馆

Simulation of Kelvin-Helmholtz Instability with Flux-Corrected Transport Method

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第5期51卷 909-913页

作者： WANG Li-Feng ye wen-hua FAN Zheng-Feng LI Ying-Jun China University of Mining and Technology （Beijing） Beijing 100083 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O. Box 8009-12 Beijing 100088 China Department of Physics Zhejiang University Hangzhou 310028 China Center for Applied Physics and Technology Peking University Beijing 100871 China

The sixth-order accurate phase error flux-corrected transport numerical algorithm is introduced, and used to simulate Kelvin-Helmholtz instability. Linear growth rates of the simulation agree with the linear theories of Kelvin Helmholtz instability. It indicates the validity and accuracy of this simulation method. The method also has good capturing ability of the instability interface deformation.

关键词： Kelvin Helmholtz instability flux-corrected transport algorithm numerical simulation

Incompressible Magnetohydrodynamic Kelvin-Helmholtz Instability with Continuous Profiles

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第3期31卷 23-26页

作者： ZHAO Kai-Ge WANG Li-Feng ye wen-hua WU Jun-Feng LI Ying-Jun State Key Laboratory for Ceomechanics and Deep Underground Engineering China University of Mining and Technology Beijing 100083 Institute of Applied Physics and Computational Mathematics Beijing 100094 HEDPS Center for Applied Physics and Technology Peking University Beijing 100871 Department of Physic Zhejiang University Hangzhou 310027

Effects of a continuous magnetic field in the direction of streaming on the incompressible Kelvin–Helmholtz instability （KHI） are investigated by solving the linear ideal magnetohydrodynamic equations. It is found that the frequency of the KHI is not influenced by the magnetic field. The magnetic field strength effect decreases the linear growth of the KHI, while the magnetic field gradient scale length effect increases its linear growth. The KHI can even be completely suppressed when the magnetic field is strong enough. The linear growth rate approaches a maximum when the magnetic field gradient scale length is large enough.

关键词： Magnetohydrodynamics

Design of an Indirect-Drive Pulse Shape for ~1.6 MJ Inertial Confinement Fusion Ignition Capsules

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第4期31卷 89-92页

作者： WANG Li-Feng WU Jun-Feng ye wen-hua FAN Zheng-Feng HE Xian-Tu Institute of Applied Physics and Computational Mathematics Beijing 100094 HEDPS Center for Applied Physics and Technology Peking Universir~y Beijing 100871

We present a design of indirect-drive pulse shape for inertial confinement fusion ignition capsules using laser energy 1.6 MJ with a moderate gain （~10） on the Shenguang 1V laser facility. The trade-off fuel compression （pressure） for resistance to the hydrodynamic instability （HI） in the recent high-foot （HF） implosion campaign [Dittrieh T t et al Phys. Rev. Lett. 112 （2014）055002] is recovered. The proposed design modifies the ＂main＂ pulse shape, which features a decompression-recompression step for the fuel shell resulting in higher areal density than that of the ＂simple＂ HF design, and thereby approaches the conditions required for ignition avoiding at the expense of more laser energy while holding the HI under control.

关键词： INERTIAL confinement fusion HYDRODYNAMICS DEUTERIUM TRITIUM SHOCK waves

On the Second Harmonic Generation through Bell-Plesset Effects in Cylindrical Geometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第4期31卷 85-88页

作者： GUO Hong-Yu YU Xiao-Jin WANG Li-Feng ye wen-hua WU Jun-Feng LI Ying-Jun State Key Laboratory for Geomeehanics and Deep Underground Engineering China University of Mining and Technology Beijing 100083 Institute of Applied Physics and Computational Mathematics Beijing 100094 HEDPS Center for Applied Physics and Technology Peking University Beijing 100871 Department of Physics Zhejiang University Hangzhou 310027

Generation of the second harmonic initiated by Bell-Plesset effects in a cylindrical geometry is studied analytically. For an initial single-mode velocity perturSation, the second-order mode-coupling formula is obtained by expanding the perturbation displacement and velocity potential up to the second-order accuracy. It is found that the initially symmetric interface evolves into a significant bubble-spike asymmetric pattern. The second-order solutions clearly show that the amplitude of the spike grows faster than that of the buSble. The temporal evolutions of the amplitudes of the 5ubSie and spike are dependent on the interface velocity Vo. The larger interface velocity leads to the smaller amplitude of the perturbation at an arbitrary interface position in a cylindrically convergent geometry.

关键词： INERTIAL confinement fusion PERTURBATION (Mathematics) SUPERNOVAE LAPLACE'S equation STOCHASTIC convergence

Phase Effect on Mode Coupling in Kelvin—Helmholtz Instability for Two-Dimensional Incompressible Fluid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第10期52卷 694-696页

作者： WANG Li-Feng TENG Ai-Ping ye wen-hua XUE Chuang FAN Zheng-Feng LI Ying-Jun China University of Mining and Technology （Beijing） Beijing 100083 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P.O. Box 8009-12 Beijing 100088 China Department of Physics Zhejiang University Hangzhou 310028 China Center for Applied Physics and Technology Peking University Beijing 100871 China

This paper studies the phase effect in mode coupling of Kelvin-Helmholtz instability in two-dimensionalincompressible *** is found that there is an important growth phenomenon of every mode in the mode *** growth changes periodically with phase difference and in the condition of our simulation the period is about0.7π.The period characteristic is apparent in all stage of the mode coupling process,especially in the relatively laterstage.

关键词： Kelvin-Helmholtz instability mode coupling phase effect

Goal-Oriented Control Systems(GOCS):From HOW to WHAT

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 816-819页

作者： wen-hua Chen the Department of Aeronautical and Automotive Engineering Loughborough UniversityLeicestershireLE113TUU.K.

Brief:New control theory is required to underpin safe design and deployment of future highly automated systems to deal with uncertain environments and complicated tasks,enabled by AI and other advanced ***-Oriented Control Systems offer potential to transform the control system design from currently instructing a control system how to perform a task to specifying what is to be achieved.

关键词： automated instru system

Atroposelective Synthesis of 2-Arylindoles via Chiral Phosphoric Acid-Catalyzed Direct Amination of Indoles

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第7期42卷 731-735页

作者： wen Bao ye-Hui Chen Yu-Wei Liu Shao-hua Xiang Bin Tan School of Pharmacy&StateKey Laboratory of Applied Organic Chemistry Lanzhou UniversityLanzhouGansu 730000China Shenzhen Grubbs Institute Department of ChemistrySouthern University of Science and TechnologyShenzhenGuangdong 518055China

Indole-based atropisomers are a very important class of axially chiral ***,the atroposelective synthesis of axially chiral 2-arylindole remains largely *** this study,we report the successful synthesis of atropisomeric 2-arylindoles using direct amination of indoles with p-quinonediimines in the presence of chiral phosphoric acid as a *** acts as an aminating reagent through formal polarity inversion of *** malonate group on the 2-aryl of 2-indoles was found to be essen-tial for high enantioselectivity of the *** could be due to the additional interaction between the ester group and the cata-lyst,as well as the intramolecular hydrogen *** findings provide a new strategy for the asymmetric construction of 2-arylindole atropisomers.

关键词： Chiral phosphoric acid Quinonediimines Direct amination Nucleophilic addition Asymmetric catalysis Enantioselectivity Axially chiral 2-arylindole Atroposelective synthesis

General formalism for dirty extreme-mass-ratio inspirals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： ye Jiang wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science Center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity are important applications of extreme-mass-ratio inspirals(EMRIs).There is still a challenge to efficiently describe various“dirty”impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study,we find the inherent linearity of the asymptotic solution of the inhomogeneous Teukolsky *** the basis of this property,we completely decouple the factors of the perturber and the background spacetime in the energy fluxes and *** the new decoupling form,the waveforms of EMRIs with non-geodesic motion in Kerr spacetime can be conveniently *** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky equation extreme-mass-ratio inspirals

Noninvasive beam diagnosis based on the TM_(010)mode

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 115-125页

作者： Chuang-ye Song wen-Hui huang Department of Engineering Physics Tsinghua University BeijingBeijing100084China of Education Beijing100084China

A resonant cavity based on the TM_(010)mode is an effective tool for noninvasive beam characterization. This technique has the advantages of a high signal-to-noise ratio, compact structure, and is related to multiple parameters compared with other beam monitors. In this study, high-precision measurements of the bunch charge, arrival time, bunch length, and energy parameters based on the TM_(010)mode are discussed. A cavity beam arrival time monitor(BAM) utilizing a phase cavity has been widely used in many facilities. Regarding bunch-length measurements, the influence of the beam energy, beam offset,and longitudinal spectrum on the TM_(010)mode are carefully considered to reduce errors, and the theoretical resolution of two cavities with different frequencies is analyzed. Owing to the dependence of the beam velocity of the beam loss factor, this method can also be used for the detection low beam energy using two cavities with the same frequency but different cavity lengths. A set of three cavities with different lengths and frequencies of 1.902 and 11.424 GHz is presented for measuring the four aforementioned parameters.

关键词： TM_(010)mode Noninvasive diagnosis Beam length Low energy